Evidence obtained by Motherboard sheds light on Microsoft “listeners” – outsourced contractors hired to improve Skype’s translation service by analyzing the audio and eventually correcting the AI-generated translations.

Although Skype says on its website that the company could examine the audio of Skype calls that users want to translate to perfect the service, it does not explicitly mention the use of humans.

The evidence obtained includes audio clips of intimate conversation, such as people chatting about personal issues like weight loss and others discussing relationship problems. More evidence shows that Microsoft is also using human contractors to listen to voice commands imparted to Cortana, its AI-powered voice assistant.

Google and Apple recently had to give up using human transcribers for their Assistant and Siri services, after media reported on the companies practices.

The evidence’s source, a Microsoft contractor working on the translations to whom Motherboard has granted anonymity, is concerned by the worryingly weak respect for users’ data privacy.

“The fact that I can even share some of this with you shows how lax things are in terms of protecting user data,” he said.

Skype launched its translator service in 2015 Skype, allowing users to empower their conversations with real-time audio translations. The service uses AI, with impressive results according to who has tried it. But apparently, the biggest names in AI technologies are still largely employing humans to back up their software and improve it along the way.

The FAQ for Skype Translator says that when people use it Skype might collect and use the conversation to “help improve Microsoft products and services”, and adds that “sentences and automatic transcripts are analyzed and any corrections are entered into the system, to build more performant services.”

There is no mention to humans listening to the audio clips coming from Skype Translator, and Microsoft’s Privacy Policy does not clarify things either.

“People use Skype to call their lovers, interview for jobs, or connect with their families abroad. Companies should be 100% transparent about the ways people’s conversations are recorded and how these recordings are being used,” said in an online chat Frederike Kaltheuner, from the activist group Privacy International.

She added that “if a sample of your voice is going to human review (for whatever reason) the system should ask them whether you are ok with that, or at least give you the option to opt-out”.

In an emailed statement to Motherboard, Microsoft said that it “collects voice data to provide and improve voice-enabled services like search, voice commands, dictation or translation services”.

“We strive to be transparent about our collection and use of voice data to ensure customers can make informed choices about when and how their voice data is used. Microsoft gets customers’ permission before collecting and using their voice data.”

“We also put in place several procedures designed to prioritize users’ privacy before sharing this data with our vendors, including de-identifying data, requiring non-disclosure agreements with vendors and their employees, and requiring that vendors meet the high privacy standards set out in European law. We continue to review the way we handle voice data to ensure we make options as clear as possible to customers and provide strong privacy protections,” the statement concluded.